.site_header__promo::after {
    content: '';
    background: url('https://ss.uooio.keenetic.pro/static/uo-tashtagol.kemobl.ru/img/georg_lenta.png');
    width: 125px;
    position: absolute;
    height: 58px;
    right: -28px;
    top: 0;
    z-index: 5;
    background-size: contain;
    rotate: 45deg;
}